#region Using Directives and Copyright Notice

// Copyright (c) 2007-2010, Computer Consultancy Pty Ltd
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//     * Neither the name of the Computer Consultancy Pty Ltd nor the
//       names of its contributors may be used to endorse or promote products
//       derived from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
// ARE DISCLAIMED. IN NO EVENT SHALL COMPUTER CONSULTANCY PTY LTD BE LIABLE 
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
// DAMAGE.

using System;
using System.Collections.Generic;
using System.Text;

using Interlace.Utilities;

#endregion

namespace Interlace.AdornedText
{
    public class LineClassifierContext
    {
        readonly string[] _previousLines;
        readonly string _currentLine;
        readonly int _currentLineNumber;
        readonly string[] _followingLines;

        public LineClassifierContext(string[] previousLines, string currentLine, int currentLineNumber, string[] followingLines)
        {
            _previousLines = previousLines;
            _currentLine = currentLine;
            _currentLineNumber = currentLineNumber;
            _followingLines = followingLines;
        }

        public IEnumerable<Pair<int, string>> PreviousLines
        {
            get 
            {
                int lineNumber = _currentLineNumber - _previousLines.Length;

                foreach (string line in _previousLines)
                {
                    yield return new Pair<int, string>(lineNumber, line);

                    lineNumber++;
                }
            }
        }

        public Pair<int, string> CurrentLine
        {
            get { return new Pair<int, string>(_currentLineNumber, _currentLine); }
        }

        public IEnumerable<Pair<int, string>> FollowingLines
        {
            get 
            {
                int lineNumber = _currentLineNumber + 1;

                foreach (string line in _followingLines)
                {
                    yield return new Pair<int, string>(lineNumber, line);

                    lineNumber++;
                }
            }
        }

        public IEnumerable<Pair<int, string>> AllLines
        {
            get
            {
                foreach (Pair<int, string> pair in PreviousLines) yield return pair;

                yield return CurrentLine;

                foreach (Pair<int, string> pair in FollowingLines) yield return pair;
            }
        }
    }
}
